Results 1 to 3 of 3

Math Help - Quadratic formula

  1. #1
    Newbie
    Joined
    May 2008
    Posts
    2

    Quadratic formula

    Can someone help me?
    Please, I'm really confused. Anyone help would be appreciated.
    I'm not really sure what to do w/ the x's in the equation....

    heres the link to the equation:
    http://img100.imageshack.us/img100/57/mathpi8.png
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member Jonboy's Avatar
    Joined
    May 2007
    From
    South Point
    Posts
    193
    have no fear

    x + \frac{1}{x} = \frac{3}{x} + 3

    Just multiply both sides by x (just the simple multiplication property):

    x[x + \frac{1}{x}] = [\frac{3}{x} + 3]x

    Distribute: x\cdot x \,+ \not x\cdot\frac{1}{\not x} = \not x\cdot \frac{3}{\not x} + 3\cdot x

    Simplify: x^2 + 1 = 3 + 3x

    Rearrange to standard form: x^2 -3x - 2 = 0

    You should get x = \frac{3}{2} \pm \frac{\sqrt{17}}{2}.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by Jonboy View Post
    have no fear

    x + \frac{1}{x} = \frac{3}{x} + 3

    Just multiply both sides by x (just the simple multiplication property):

    x[x + \frac{1}{x}] = [\frac{3}{x} + 3]x

    Distribute: x\cdot x \,+ \not x\cdot\frac{1}{\not x} = \not x\cdot \frac{3}{\not x} + 3\cdot x

    Simplify: x^2 + 1 = 3 + 3x

    Rearrange to standard form: x^2 -3x - 2 = 0

    You should get x = \frac{3}{2} \pm \frac{\sqrt{17}}{2}.
    To get large brackets in LaTeX tou can use "\left[ ... \right]", these will be adaptive and give the right sized brackets for what is between, or "\big[ ... \big]"
    or "\Big[ ... \Big]", "\bigg[ ... \bigg]", "\Bigg[ ...\Bigg]".

    So using each of these we have:

    x\left[ x + \frac{1}{x} \right] = \left[ \frac{3}{x} + 3 \right] x

    x \big[ x + \frac{1}{x} \big] = \big[ \frac{3}{x} + 3 \big] x

    x \Big[ x + \frac{1}{x} \Big] = \Big[ \frac{3}{x} + 3 \Big] x

    x \bigg[ x + \frac{1}{x} \bigg] = \bigg[ \frac{3}{x} + 3 \bigg] x

    x \Bigg[ x + \frac{1}{x} \Bigg] = \Bigg[ \frac{3}{x} + 3 \Bigg] x

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Quadratic Formula.
    Posted in the Algebra Forum
    Replies: 3
    Last Post: March 23rd 2011, 11:19 AM
  2. quadratic formula
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 25th 2010, 11:08 AM
  3. quadratic formula
    Posted in the Algebra Forum
    Replies: 3
    Last Post: September 2nd 2009, 02:57 PM
  4. quadratic formula
    Posted in the Algebra Forum
    Replies: 4
    Last Post: April 14th 2008, 10:47 PM
  5. Quadratic Formula
    Posted in the Algebra Forum
    Replies: 2
    Last Post: April 8th 2008, 04:05 PM

Search Tags


/mathhelpforum @mathhelpforum